Selection of oxide supports to anchor desirable bimetallic structures for ethanol reforming and 1,3-butadiene hydrogenation

Abstract

Ethanol reforming and 1,3-butadiene hydrogenation reactions were studied on Pt-Ni bimetallic and monometallic catalysts supported on several supports, including γ-Al 2 O 3 , SiO 2 , TiO 2 , CeO 2 , and high surface area (HSA) and low surface area (LSA) ZrO 2 , to elucidate the effect of oxide supports on the bimetallic structures and catalytic activity. The catalysts were prepared by co-impregnation and were characterized by pulse CO chemisorption, transmission electron microscopy, and extended X-ray absorption fine structure. Reactions were carried out in a Fourier transform infrared batch reactor. The supports strongly affected the catalytic activity. For ethanol reforming, the activities of the Pt-Ni bimetallic catalysts were in the order TiO 2 > SiO 2 > γ-Al 2 O 3 ≈ LSA-ZrO 2 > CeO 2 > HSA-ZrO 2 ; while for 1,3-butadiene hydrogenation, the order was SiO 2 > CeO 2 > γ-Al 2 O 3 > LSA-ZrO 2 > HSA-ZrO 2 ≈ TiO 2 . For the hydrogenation reaction, the Pt-Ni bimetallic catalysts outperformed the Pt and Ni monometallic catalysts; in contrast, for the reforming reaction, synergetic bimetallic effects were only found on SiO 2 , TiO 2 , and HSA-ZrO 2 . For ethanol reforming, the Pt-Ni bimetallic catalyst activity is in the order TiO 2 > SiO 2 > γ-Al 2 O 3 ≈ LSA-ZrO 2 > CeO 2 > HSA-ZrO 2 ; while for 1,3-butadiene hydrogenation, the activity follows the trend of SiO 2 > CeO 2 > γ-Al 2 O 3 > LSA-ZrO 2 > HSA-ZrO 2 ≈ TiO 2 .